Bonaire, whose coastal waters have been a marine park since 1979, now encourages lionfish hunting with special spear guns to control the destructive nonnative species.

Photo: Bruce Schnaak

Bonaire, whose coastal waters have been a marine park since 1979,...

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Lionfish, native to the Pacific Ocean, have invaded the Caribbean and the Atlantic, where they wreak environmental calamity.

Photo: Bruce Schnaak

Lionfish, native to the Pacific Ocean, have invaded the Caribbean...

Image 3 of 3

Lionfish live in the shallows and at depths of more than 100 feet. In the Pacific, they reproduce once every four months; in the Caribbean, they breed every six to eight weeks, releasing 2 million eggs a year, 75 percent of which survive because of a mucous coating around the egg sac that Atlantic fish won't eat.

Fifty feet down in the turquoise waters off Bonaire, I was lying in wait, ready to take out an exotic enemy whose sin was having stumbled into the wrong side of the world. When the spiny scoundrel poked up from behind some coral, it wasn't clear whether it had spotted me and the weapon in my hand, built specifically to end its life, so I took aim.

Missing was not an option. The ocean couldn't afford failure.

The prey was the lionfish, a species native to the Pacific Ocean that since the 1990s has spread - probably released in the Atlantic by an aquarium owner who didn't know better - from Florida, up the Eastern seaboard, down through the Caribbean and toward Brazil.

It has no natural predators and eats almost everything in sight, but the peril it posed was not immediately understood. Few islands acted quickly in containing its spread. But things are different on environmentally conscious Bonaire, where the lionfish first appeared in late 2009. The coastal waters of the Dutch Caribbean island have been a protected marine park since 1979, and spearguns, among other things, are banned.

In a startling about-face, environmental leaders now sanction the slaughter of lionfish by professionals and tourists instructed in the use of special lionfish-hunting tools - including divers like me. An unholy trinity of ecological protection, "voluntourism" and old-fashioned blood sport has given first-time and repeat visitors a new reason to travel to Bonaire.

To be snipers.

Deadly beauty

Spectacular to behold, the red lionfish wears red and white stripes, and its long, venomous spines ruffle like a mane of ribbons underwater. It is a dangerous beauty: Its stomach can stretch to 30 times its size. It eats not only juvenile fish, but almost everything, including octopus, lobster, shrimp, amberjack, grouper and snapper. With no fish to graze on the corals and sponges, the reefs become smothered by algae. Starved of oxygen, they die.

Lionfish live in the shallows and at depths of more than 100 feet. In the Pacific, they reproduce once every four months; in the Caribbean, they breed every six to eight weeks, releasing 2 million eggs a year, 75 percent of which survive because of a mucous coating around the egg sac that Atlantic fish won't eat.

On conservation-minded Bonaire, a gentle approach came first: Divers carried nets to scoop the lionfish up, much like trapping butterflies, but the lionfish reproduced so rapidly that the netters couldn't keep up. Within a year, it wasn't unusual to see 10 to 20 lionfish per dive.

Officials at Stinapa, the island's marine park, changed course, allowing the hunting of lionfish with tools that did not work on other fish. In 2011, they gave dive shops permission to teach lionfish hunting classes. In effect, an island that hadn't allowed fishing was handing out weapons in this war.

One of the world's largest dive organizations, the Professional Association of Dive Instructors, understands the risk that lionfish pose and supports the teaching of its Invasive Lionfish Specialty course.

"Active hunting has become a means of trying to control the spread of this highly invasive species, which negatively impacts the ocean and well-being of the local economies" that depend heavily on tourism, said Brad Smith, training manager of PADI Americas, in an e-mail. "The PADI organization believes with the right training and under the guidelines of local laws, underwater hunting and collecting can be done responsibly and with respect for the environment."

Planning the hunt

At home, I had joined the Bonaire Lionfish Hunters group on Facebook, and arranged to join a research dive on the island with members of a marine ecology program operating through the Council on International Education Exchange.

A few hours after I got off the plane, I jumped in the water with Fadilah Ali of the University of Southampton in Great Britain, a doctoral student who has been conducting a survey of the lionfish invasion since 2009. Also on the trip were Capt. Menno de Bree, who donated the use of his boat for Ali's expeditions, and a dozen volunteers and marine park officials ready to hunt lionfish and make notations about those that escaped capture. Our location was a site on Klein Bonaire, a small island off the coast.

We jumped in at sunset, when lionfish come out to eat. I couldn't believe the scene: Lionfish hovered here and there, their wiggly white spines fluttering over the reef. My dive buddy, Bas Tol, who holds the island's record for lionfish kills at more than 3,000, was busy looking over, under and around all coral heads with crevices and the exposed ledges where lionfish like to sit.

I was watching the best, and taking notes about his style - every few minutes, he was slowly gliding into place and hovering as he positioned his special lionfish-hunting tool before firing into the meatiest part of its body to make sure that - unlike others with less experience - he didn't miss or allow it to wiggle free.

I was surprised at my own reaction. You can't talk underwater, but inside my head there was a surprisingly blunt, one-sided conversation going on.

"Die (insert expletive), die!"

When we made it back to land, the slain lionfish (several dozen in all) were measured for length and their stomach contents examined to learn more about their growth patterns and eating habits.

Thanks to the 100 or so certified hunters on Bonaire, lionfish are a rarer sight between the surface and 100 feet down, where most of the baby fish live and where they grow into adults - giving some hope that hunting efforts will sustain the reef. Below 100 feet, it's another story - de Bree told me that a researcher on a submarine from Curacao saw so many in the deep that he began to cry.

Necessary killing

Some, but not all, lionfish hunters are motivated by blood lust. Paula Anderson, 58, a molecular lab medical technologist from Richmond, Va., said she would "rather take a cockroach outside than kill it," but was appalled by the difference she noticed in the pristine reefs observed on her first visit in 2004 to reefs blanketed with lionfish on a subsequent visit in 2010.

She became certified to hunt in May.

"I always like to have a purpose to what I do, and this is a new spin on that."

Veterinarian Becky Hauser, 44, of Valders, Wis., hunts lionfish because she was stunned by the sixfold increase in their breeding cycles in the Atlantic. "I thought, 'Death to lionfish,' " she said. "Let's get these suckers off the reef."

Similarly motivated, I signed up for a daylong $150 course with Bas Noij of VIP Diving, a 10-hour undertaking that consisted of classroom instruction about anatomy and safety (lionfish stings are painful but not fatal), target practice on land with a water bottle standing in for the lionfish, and two dives to search for my quarry.

Divers use a metal rod called an ELF, an acronym for "eliminate lion fish." The rudimentary, arm-length speargun has a spring-loaded trigger and a three-pronged tip that jettisons into the lionfish's torso. The diver then stuffs the carcass into a zookeeper - a PVC tube with a perforated lid - to bring the catch to the surface.

Apparently, there's more to hunting lionfish than point and shoot. You have to hit the lionfish in the meatiest part of its torso, not the tail, to kill it; wait until you're 2 inches away before firing, or the prongs will not penetrate the lionfish's body and it can swim free; and don't take the shot if you're not sure.

Lionfish may be sitting ducks, but they are also quick studies. Noij told me that lionfish learn after one missed shot that the bubbles from a diver's regulator means they are being hunted, and they dart away on sight.

Plunging in

It was time to take the plunge, with Noij and a divemaster he brought along for safety.

Not 10 minutes into the dive near a site called Larry's Lair on the southern end of the leeward side of the island, at 50 feet, amid schools of brown chromis, a few queen angels and a lush coral landscape dotted by purple tube sponges, Noij turned to me and made the hand signal for lionfish - an L-shape with his thumb and index finger.

Was I ready? Not really, but there wasn't a choice. The only way I could obtain my certification card was to take a shot, and I really wanted that card.

He handed me the ELF. I took a deep breath and stared at the fish, nestled in a sandy patch under a coral head. I exhaled, which caused me to glide down toward the lionfish. Pointing the ELF, I waited until I was almost touching the darn thing's eyeballs before I hit the trigger. In a flash, it was dead. There was no sound, no blood, no fanfare. But it was exhilarating to know the reef had been cleared of one more pest.

Back on the surface, I learned that the lionfish has one redeeming quality on Bonaire. At lunchtime, Hagen Wegerer, the chef at the Cactus Blue food truck at the island's kiteboarding beach, kindly grilled up our catch, which Noij had quickly (and safely) filleted - and which tasted like petrale sole.

I can't be certain, but it's probably the only situation in which a sniper gets to eat her prey.

If you go

GETTING THERE

United Airlines offers the most direct route from San Francisco (one stop), with two flights a week (one Saturday, one Sunday) through Houston, and one Saturday through Newark. The flight to Bonaire is a red-eye that arrives before 6 a.m., so take care with dates when booking your departure (if you want to arrive on Saturday morning, you may need to depart from San Francisco on Friday). Advance fares typically run $720 round trip.